He said to him, “Follow me.” And he got up and followed him. (Matthew 9:9)

Why did Jesus not call Matthew at the same time as He called Peter and John and the rest?
He came to each one at a particular time when He knew that they would respond to Him. He came at a different time to call Matthew when He was assured that Matthew would surrender to His call. For He Who is acquainted with our inmost hearts and knows the secrets of our minds, knows when each one of us is ready to respond fully - St John Chrysostom